Neurobiology Driving Hyperactivity in Activity-Based Anorexia

Abstract

Hyperactivity in anorexia nervosa is difficult to control and negatively impacts outcome. Hyperactivity is a key driving force to starvation in an animal model named activity-based anorexia (ABA). Recent research has started unraveling what mechanisms underlie this hyperactivity. Besides a general increase in locomotor activity that may be an expression of foraging behavior and involves frontal brain regions, the increased locomotor activity expressed before food is presented (food anticipatory behavior or FAA) involves hypothalamic neural circuits. Ghrelin plays a role in FAA, whereas decreased leptin signaling is involved in both aspects of increased locomotor activity. We hypothesize that increased ghrelin and decreased leptin signaling drive the activity of dopamine neurons in the ventral tegmental area. In anorexia nervosa patients, this altered activity of the dopamine system may be involved not only in hyperactivity but also in aberrant cognitive processing related to food.

Exercise Addiction and Compulsive Exercising: Relationship to Eating Disorders, Substance Use Disorders, and Addictive Disorders

“…Animal research has the advantage of being able to more closely examine possible mechanistic pathways in the brain that may be responsible for this effect. Specifically, the association between hypothalamic-pituitary-adrenal (HPA) axis activity and food restriction increased in physical activity, and this relationship is mediated through body fat levels (Adan et al, 2011;Duclos, Bouchet, Vettier, & Richard, 2005;Hamer & Karageorghis, 2007). However, research examining athletic-based anorexia is difficult to replicate in humans, and explanations of this effect typically include some recognition of culture (Epling & Pierce, 1996).…”

Compulsivity in anorexia nervosa: a transdiagnostic concept

“…Rats on a restricted diet given free access to a running wheel will increase activity to the point of death (Routtenberg and Kuznesof, 1967; Adan et al, 2011). Interestingly, young female rats, as in human AN, show particular susceptibility to this effect (Hancock and Grant, 2009).…”

Effects of Long Acting Methylphenidate on Ghrelin Levels in Male Children with Attention Deficit Hyperactivity Disorder: An Open Label Trial

“…Increased ghrelin might be associated with hyperactivity, which is often seen in anorexia patients. In patients with anorexia nervosa, this altered activity of the dopamine system due to the increase of ghrelin may be involved not only in hyperactivity but also in aberrant cognitive processing related to food 85 . In response to acute physical exercise, plasma ghrelin levels tend to decrease 86 .…”